Quaternary II-VI materials for photonics

Abstract

A photonic device includes a substrate and a region comprised of a quaternary Group II-VI material supported by the substrate. Examples of quaternary Group II-IV alloys include Hg, Zn, S and Se; Hg, Zn, Se and Te; Zn, S, Se and Te; Zn, Mn, S and Se; and Hg, Cd, Zn and S. By example, the quaternary material HgZnSSe, which is lattice-matched to ZnSe or GaAs, and the quaternary material HgZnSeTe, which is lattice-matched to ZnTe or GaSb, are employed in the construction of lasers, LEDs and detectors suitable for use over a range of wavelengths. The energy bandgap of the HgZnSSe alloy may be varied to achieve emission over the entire visible spectrum while the HgZnSeTe alloy emits within the spectrum from green to far infrared.

What is claimed is: 
     
       1. A photonic device including a region comprised of a quaternary Group II-VI alloy containing Hg as one atomic constituent and a substrate supporting the region, the substrate having a characteristic lattice constant, and wherein the quaternary Group II-VI alloy has a composition selected for substantially lattice matching the region to the substrate and also for providing the region with an energy bandgap associated with a wavelength of interest. 
     
     
       2. A photonic device as set forth in claim 1 wherein the quaternary Group II-VI alloy is comprised of Hg.sub.(1-x) Zn x  S.sub.(1-y) Se y  where x and y each have a value greater than zero and less than one. 
     
     
       3. A photonic device as set forth in claim 1 wherein the quaternary Group II-VI alloy is comprised of Hg.sub.(1-x) Zn x  Se.sub.(1-y) Te y  where x and y each have a value greater than zero and less than one. 
     
     
       4. A photonic device as set forth in claim 1 wherein the quaternary Group II-VI alloy is comprised of Hg.sub.(1-x) A x  B.sub.(1-y) C y  where A is Zn or Cd, B is S, Se or Te and C is S, Se or Te and x and y each have a value greater than zero and less than one. 
     
     
       5. A photonic device as set forth in claim 1 wherein the quaternary Group II-VI alloy is comprised of Hg.sub.(1-x-y) Cd x  Zn y  C where C is S, Se or Te and x and y each have a value greater than zero and less than one. 
     
     
       6. A photonic device as set forth in claim 1 wherein the quaternary Group II-VI alloy is comprised of Hg.sub.(1-x-y) Cd x  Zn y  S where x and y each have a value greater than zero and less than one. 
     
     
       7. A photonic device as set forth in claim 1 wherein the substrate is comprised of material selected from the group consisting of GaAs and ZnSe. 
     
     
       8. A photonic device as set forth in claim 1 wherein the substrate is comprised of material selected from the group consisting of ZnTe, GaAs, and GaSb and combinations thereof. 
     
     
       9. A photonic device as set forth in claim 1 wherein the region is comprised of a substantially homogeneous epitaxial layer. 
     
     
       10. A photonic device as set forth in claim 1 wherein the region is comprised of a plurality of epitaxial layers arranged as a multilayered structure. 
     
     
       11. A photonic device as set forth in claim 10 wherein the multilayered structure is comprised of a first plurality of layers selected from the group comprising (i) Hg.sub.(1-x) A×B.sub.(1-y) C y  where A is Zn or Cd, B is S, Se or Te and C is S, Se or Te and x and y each have a value greater than zero and less than one and (ii) Hg.sub.(1-x-y) Cd x  Zn y  C where C is S, Se or Te and x and y each have a value greater than zero and less than one, individual ones of which alternate with individual ones of a second plurality of layers selected from the group comprising (i) Hg.sub.(1-x') A x'  B.sub.(1-y') C y , where A is Zn or Cd, B is S, Se or Te and C is S, Se or Te and x' and y' each have a value greater than zero and less than one and (ii) Hg.sub.(1-x'-y') Cd x'  Zn y'  C where C is S, Se or Te and x' and y' each have a value greater than zero and less than one, with x, y and x', y' selected so that the lattice parameters of the individual layers are all equal, but the energy gaps are different. 
     
     
       12. A photonic device as set forth in claim 1 wherein the wavelength of interest lies within the visible spectrum. 
     
     
       13. A double heterojunction injection laser comprising: a substrate;   a first cladding layer overlying the substrate, the first cladding layer being comprised of a binary or a ternary Group II-VI material having a first type of electrical conductivity;   an active region overlying the first cladding layer, the active region being comprised of a quaternary Group II-VI alloy containing Hg as one atomic constituent; and   a second cladding layer overlying the active region, the second cladding layer being comprised of a binary or a ternary Group II-VI material having a second type of electrical conductivity.   
     
     
       14. A double heterojunction injection laser as set forth in claim 13 wherein the substrate has a characteristic lattice constant and wherein the quaternary Group II-VI alloy is comprised of Hg.sub.(1-x) Zn x  S.sub.(1-y) Se y  where x and y each have a value greater than zero and less than one for substantially lattice matching the active region to the substrate and also for determining the energy bandgap of the quaternary Group II-VI alloy such that the alloy emits electromagnetic radiation having a characteristic wavelength within the range of wavelengths associated with red light to violet light. 
     
     
       15. A double heterojunction injection laser as set forth in claim 13 wherein the active region is comprised of a substantially homogeneous epitaxial layer. 
     
     
       16. A double heterojunction injection laser set forth in claim 13 wherein the active region is comprised of a first plurality of layers selected from the group comprising (i) Hg.sub.(1-x) A x  B.sub.(1-y) C y  where A is Zn or Cd, B is S, Se or Te and C is S, Se or Te and x and y each have a value greater than zero and less than one and (ii) Hg.sub.(1-x-y) Cd x  Zn y  C where C is S, Se or Te and x and y each have a value greater than zero and less than one, individual ones of which alternate with individual ones of a second plurality of layers selected from the group comprising (i) Hg.sub.(1-x') A x'  B.sub.(1-y') C y'  where A is Zn or Cd, B is S, Se or Te and C is S, Se or Te and x' and y' each have a value greater than zero and less than one and (ii) Hg.sub.(1-x'-y') Cd x'  Zn y'  C where C is S, Se or Te and x' and y' each have a value greater than zero and less than one, with x, y and x', y' selected so that the lattice parameters of the individual layers are all equal, but the energy gaps are different.